a comment out of corn and to be affective medications have to fulfill certain criteria they must be stable but resistant they need to have a long shelf life and reach certain parts of the body where they're needed so they have to remain stable during and sematic reactions. that stability is also the reason why the body doesn't completely absorbed medications so a proportion of the medications you take are eliminated by a urine. up to seventy percent of the dye cliff a knack you swallow is excrete it again residue from creams and gels is also rinsed away in the shower bath and ends up in the waste water. the bavarian researches have built a reactor that can break down stable drug residues in it wastewater is post with ozone the process is already used to kill. but it also breaks down drug residues into their constituent parts.